The invention is based on a measuring device. Measuring devices are used for example in brake systems of motor vehicles, which are electrohydraulically actuated or regulated. Known applications are antilock brake systems or brake systems without mechanical coupling between the brake actuation pedal and the master cylinder.
The main parameters for regulating these electrohydraulic brake systems are the operating pressures that occur in the brake circuits. These can be detected by brake sensors, converted into electrical signals, and, together with other sensors signals, can be processed in a control unit into control signals for the brake assembly. This requires a relatively large number of individual parts, which must be separately fastened and connected by way of hydraulic or electric lines. When routing hydraulic lines, in particular a possible production of air cushions in the measuring circuits must be prevented because air conditions of this kind can cause incorrect measurements and in the extreme case, can lead to malfunctions of the brake system. A production of air cushions is particularly encouraged when conventional, inexpensive pressure sensors with cup-shaped measuring cells are used.
In keeping with these objects, one feature of present invention resides, briefly stated in a measuring device, in which at least one sensor and at least one circuit holder are combined into a measuring unit with the aid of a console.
A measuring device with these characterizing features has the advantage over the prior art of a measuring device that is combined into a separate assembly, which in particular can be fastened to the hydraulic block of a brake assembly and as a result, has a relatively compact structure. The necessary electric and hydraulic line routing from or to the measuring device can therefore take place in a comparatively short and direct manner so that to a large extent, hollow chambers that are not flowed through in the measuring circuits can be prevented. Also, the hollow chambers required by the cup-shaped embodiment of the pressure sensors are reduced to an obligatory minimum in the measuring device according to the invention. The measuring device has a particularly embodied console with recesses for the sensors and the circuit holders. As a result, the console also protects these sensitive components against mechanical and thermal stresses. The measuring device is also easily accessible when serviced and can be replaced with a small number of operations and using a standard tool.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Exemplary embodiments of the invention are shown in the drawings and will be explained in more detail in the subsequent description.
FIG. 1 is a perspective view that shows a first exemplary embodiment of a measuring device,
FIG. 2 shows the measuring device according to FIG. 1 in a cross section along the cutting line IIxe2x80x94II in FIG. 1.
FIG. 3 shows a perspective view of a second exemplary embodiment;
FIGS. 4 and 5 show cross sections along the line IVxe2x80x94IV in FIG. 3, which disclose different possibilities for routing the measuring tube to the sensors.